GB2118660A

GB2118660A - Screw-receiving wall plug

Info

Publication number: GB2118660A
Application number: GB08208047A
Authority: GB
Inventors: Frank Pitts
Original assignee: R L BUREAU D ETUDES ET DE RECH
Current assignee: R L BUREAU D ETUDES ET DE RECH
Priority date: 1982-03-19
Filing date: 1982-03-19
Publication date: 1983-11-02

Abstract

A device for fastening an article to a wall comprises a hollow cylindrical plug 1 to be positioned in a hole 9 in the wall to receive a screw 10 and a grommet 6 for receiving the screw 10 having an external diameter equal to or slightly less than that of the plug 1. The plug 1 and grommet 6 may be integral. The grommet 6 has a bevelled flange at its outer end. <IMAGE>

Description

SPECIFICATION Fastening device This invention relates to a method and a device suitable for fastening an article to a wall or like structure.

It is known to fasten articles such as sheets of wood or like material to a wall by means of a screw passing through the article and into a plug which is mounted in a hole in the wall, the plug having an interior diameter such that the threads of the screw bite the interior surface of the plug.

Typically, the plug has an exterior diameter of about 6 mm and an interior diameter of 4.5 mm so that a 4.5 mm screw may be used. The hole in the article to receive the screw should have a diameter corresponding to that of the screw: a larger hole in the article would generally give undesirable play between the article and the screw and the whole fastening would be insecure.

The diameter of the hole in the article is thus less than that of the hole in the wall and separate drilling operations, requiring different sized drill bits, are necessary.

A typical procedure for securing the article is to drill holes, for example of 4.5 mm, at the desired locations in the article, place the article against the wall in the desired final position, mark the wall using a pencil or the like passing through the holes, remove the article, drill holes of greater diameter (e.g. 6 mm) at the marked points in the wall, insert plugs in the holes in the wall, return the article to its desired position and attach it to the wall by screws passing through the holes of the article and into the plugs.

The present invention is intended to provide a simpler and more convenient method of fastening which requires fewer individual operations and in which the holes in the wall and the article are of the same size.

According to one aspect of the invention there is provided a fastening device comprising a hollow cylindrical plug adapted to be positioned in a hole in a wall and receive a screw to engage the interior surface of the plug, and a grommet capable of receiving and engaging the screw having an external diameter substantially equal to or slightly less than the external diameter of the plug.

According to another aspect of the invention there is provided a method of fastening an article to a wall or like structure in which the article is positioned against the wall, a hole is drilled through both the article and the wall, a hollow cylindrical plug is passed into the hole in the wall through the hole in the article, a grommet is provided in the hole in the article and a screw is passed through the grommet to engage the interior surface of the plug.

The plug and grommet may be made as separate units or as an integral unit, the grommet then constituting an extension of the plug. The grommet may be generally cylindrical and have a flange at its outer end which is bevelled on its interior surface to engage the head of the screw, which may be a standard wood screw, and to fit a countersinking in the hole in the article. The grommet and plug may be made of metal or a plastic material having an adequate hardness. The length of the grommet is preferably substantially equal to the thickness of the article to be fastened although it may be greater or less.

The plug may comprise a hollow cylinder having an open end to receive the screw. The outer surface of the plug may be provided with outstanding tangs or grooves to engage the sides of the hole in the wall and prevent removal of the plug. The plug may be provided with a longitudinal slit and have an interior diameter such that it expands axially when a screw is inserted, thus urging the plug against the sides of the hole.

Fastening devices according to embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a section of a fastening device according to the invention, Figure 2 shows a similar section ofa fastening device according to another embodiment, Figure 3 shows the manner in which a device of Figure 1 or Figure 2 is used for securing a board to a wall.

The device shown in Figure 1 comprises a hollow cylindrical body 1 of plastics material which is closed at one end. Body 1 has an exterior diameter of 6 mm and a uniform internal diameter such that the internal wall of the body can grip the thread of a 4.5 mm diameter screw inserted in the body from the open end. The outer surface of the body is provided with transverse grooves 2 and resilient tangs 3 projecting from the outside surface towards the open end of the cylinder: also the closed end of the cylinder has a slit 4 allowing the closed end to expand radially when a screw is inserted in the body.When the body is positioned inside a 6 mm diameter hole drilled in a wall the outwardly projecting tangs 3, compressed radially inwardly by the wall, prevent the body being removed and when the 4.5 mm screw is inserted in the body the closed end tends to expand radially, slit 4 being pushed open, so that the outer surface of the closed end of the body is compressed against the wall and grooves 2 ensure a firm grip between the wall and the body.

A cylindrical grommet 5 has an external diameter the same as or slightly less than that of body 1 and has an internal diameter such that a 4.5 mm screw may pass through it without substantial resistance. The grommet is provided with a flange 6 at one end and the interior rim at that end is bevelled to receive the head of the screw.

The grommet may be of metal or a hard plastics material.

The manner in which the device of Figure 1 may be used for attaching a board to a wall will now be described with reference to Figure 3. The board 7 is first placed in its desired position against wall 8. A single hole 9 is then drilled through both the board and the wall using a 6 mm bit. After drilling the hole in the board is countersunk. With the board still in place the cylindrical plug 1 is then inserted into the hole so that it lodges inside the wall 8. After insertion the open end of the plug may be flush with the wall surface or located inside the wall. Grommet 6 is then inserted in the portion of the hole passing through the board, the flange 6 being flush with the outer surface of the board, and screw 10 is screwed into the hole.The screw bits the interior of the plug body and urges it radially outwardly, thus securing it in the wall, and head 11 of the screw holds the board in place.

The fastening device shown in Figure 2 is similar to that of Figure 1 and is used in the same way. However in this case the grommet 5 is integral with the plug body 1 and is formed as a cylindrical extension of the plug body. The plug body and grommet are then inserted in the hole together to achieve the same result as that shown in Figure 3. In this embodiment the combined plug and grommet may be made of metal or of a plastics material having sufficient rigidity.

It will be appreciated that attachment of a board or the like to a wall using the abovedescribed fastener is a very simple operation as the board, once placed in its desired position on the wall, need not be removed and the hole required is easily drilled using a single drill bit.

The fastener may be used with walls of plaster, brick, concrete or any other material which can be drilled. The member to be supported on the wall may be of timber, hardboard, metal or any other material. The fastener may be used for fastening flat sheets of board to a wall to receive ceramic tiles or other surface finish, for fastening supports for shelving and for many other purposes.

Claims

1. A fastening device comprising a hollow cylindrical plug adapted to be positioned in a hole in a wall and receive a screw to engage the interior surface of the plug, and a grommet capable of receiving an engaging the screw having an external diameter substantially equal to or slightly less than the external diameter of the plug.

2. A device according to Claim 1, in which the grommet is integral with the plug.

3. A method of fastening an article to a wall or the like structure in which the article is positioned against the wall, a hole is drilled through both the article and the wall, a hollow cylindrical plug is passed into the hole in the wall through the hole in the article, a grommet is provided in the hole in the article and a screw is passed through the grommet to engage the interior surface of the plug.